Catalogger.NET/Catalogger.Backend/Bot/Responders/Guilds/GuildMemberAddResponder.cs

using Catalogger.Backend.Cache;
using Catalogger.Backend.Cache.InMemoryCache;
using Catalogger.Backend.Database;
using Catalogger.Backend.Database.Queries;
using Catalogger.Backend.Extensions;
using Catalogger.Backend.Services;
using Humanizer;
using Remora.Discord.API;
using Remora.Discord.API.Abstractions.Gateway.Events;
using Remora.Discord.API.Abstractions.Objects;
using Remora.Discord.API.Abstractions.Rest;
using Remora.Discord.API.Objects;
using Remora.Discord.Extensions.Embeds;
using Remora.Discord.Gateway.Responders;
using Remora.Results;

namespace Catalogger.Backend.Bot.Responders.Guilds;

public class GuildMemberAddResponder(
    ILogger logger,
    DatabaseContext db,
    IMemberCache memberCache,
    UserCache userCache,
    WebhookExecutorService webhookExecutor,
    IDiscordRestGuildAPI guildApi,
    PluralkitApiService pluralkitApi
) : IResponder<IGuildMemberAdd>
{
    private readonly ILogger _logger = logger.ForContext<GuildMemberAddResponder>();
    private static readonly TimeSpan NewAccountThreshold = 7.Days();

    public async Task<Result> RespondAsync(IGuildMemberAdd member, CancellationToken ct = default)
    {
        await memberCache.SetAsync(member.GuildID, member);

        var user = member.User.GetOrThrow();

        var builder = new EmbedBuilder()
            .WithTitle("Member joined")
            .WithColour(DiscordUtils.Green)
            .WithAuthor(user.Tag(), null, user.AvatarUrl())
            .WithDescription($"<@{user.ID}>")
            .WithCurrentTimestamp()
            .WithFooter($"ID: {user.ID}");

        var guildConfig = await db.GetGuildAsync(member.GuildID, ct);
        var guildRes = await guildApi.GetGuildAsync(member.GuildID, withCounts: true, ct);
        if (guildRes.IsSuccess)
            builder.Description +=
                $"\n{guildRes.Entity.ApproximateMemberCount.Value.Ordinalize()} to join";

        builder.Description +=
            $"\ncreated {user.ID.Timestamp.Prettify()} ago\n<t:{user.ID.Timestamp.ToUnixTimeSeconds()}:F>";

        var pkSystem = await pluralkitApi.GetPluralKitSystemAsync(user.ID.Value, ct);
        if (pkSystem != null)
        {
            var createdAt =
                pkSystem.Created != null
                    ? $"{pkSystem.Created.Value.Prettify()} ago (<t:{pkSystem.Created.Value.ToUnixTimeSeconds()}:F>)"
                    : "*(unknown)*";
            builder.AddField(
                "PluralKit system",
                $"""
                **ID:** {pkSystem.Id} (`{pkSystem.Uuid}`)
                **Name:** {pkSystem.Name ?? "*(none)*"}
                **Tag:** {pkSystem.Tag ?? "*(none)*"}
                **Created:** {createdAt}
                """
            );
        }

        // TODO: find used invite

        List<Embed> embeds = [builder.Build().GetOrThrow()];

        if (user.ID.Timestamp > DateTimeOffset.Now - NewAccountThreshold)
        {
            embeds.Add(
                new EmbedBuilder()
                    .WithTitle("New account")
                    .WithColour(DiscordUtils.Orange)
                    .WithDescription($"\u26a0\ufe0f Created {user.ID.Timestamp.Prettify()} ago")
                    .Build()
                    .GetOrThrow()
            );
        }

        var watchlist = await db.GetWatchlistEntryAsync(member.GuildID, user.ID, ct);
        if (watchlist != null)
        {
            var moderator = await userCache.GetUserAsync(
                DiscordSnowflake.New(watchlist.ModeratorId)
            );
            var mod =
                moderator != null
                    ? $"{moderator.Tag()} (<@{moderator.ID}>)"
                    : $"<@{watchlist.ModeratorId}>";

            embeds.Add(
                new EmbedBuilder()
                    .WithTitle("⚠️ User on watchlist")
                    .WithColour(DiscordUtils.Red)
                    .WithDescription(
                        $"**{user.Tag()}** is on this server's watch list.\n\n{watchlist.Reason}"
                    )
                    .WithFooter($"ID: {user.ID} | Added")
                    .WithTimestamp(watchlist.AddedAt.ToDateTimeOffset())
                    .AddField("Moderator", mod)
                    .GetOrThrow()
                    .Build()
                    .GetOrThrow()
            );
        }

        if (pkSystem != null)
        {
            if (
                guildConfig.BannedSystems.Contains(pkSystem.Id)
                || guildConfig.BannedSystems.Contains(pkSystem.Uuid.ToString())
            )
            {
                embeds.Add(
                    new EmbedBuilder()
                        .WithTitle("Banned system")
                        .WithDescription(
                            "\u26a0\ufe0f The system associated with this account has been banned from the server."
                        )
                        .WithColour(DiscordUtils.Red)
                        .WithFooter($"ID: {pkSystem.Id}")
                        .Build()
                        .GetOrThrow()
                );
            }
        }

        if (embeds.Count > 1)
            await webhookExecutor.SendLogAsync(
                guildConfig.Channels.GuildMemberAdd,
                embeds.Cast<IEmbed>().ToList(),
                []
            );
        else
            webhookExecutor.QueueLog(guildConfig.Channels.GuildMemberAdd, embeds[0]);

        return Result.Success;
    }
}